Spark plug



Sept. 4, 1923. 1,467,139 E. T. CURRAN S PARK PLUG Filed Sent. 20. 1921 1 W If Patented Sept. 4, 1923..

EDWARD '1. CUBBAN, OI DETROIT, MICHIGAN.

SPARK PLUG.

Application filed September 20, 1921. Serial in. 501,891.

To all whom it may com-em:

Be it known that, I, EDWARD T. CpaRAN, a citizen of the United States, residin at Detroit, in the county of Wayne and ate of Michigan, have invented a certain new and useful Spark Plug, of which the following is a specification.

This invention is a spark plug of the general character shown in my copending application, Serial No. 162,990, filed A r11 20th, 1921, namely, a plug so constructe as to provide for the introduction of the priming fluid through the plug into the associated cylinder; to permit of the introduction of water or some other decarbonizing medium through the plug into the cylinder; and to permit of the blowing oil of carbon and oil deposits through the plug.

The present invention embodies several novel features, among which may be mentioned the formation of the plug in such manner that carbon blown out through the plug partakes, in its passage through the plug, of a substantially straight path.

It has been common heretofore to tap a hole in the side of a, conventional plug as low down on the plug as possible and associate a valve priming cup with said tapped hole by means of an angular union, so that priming fluids might be introduced into the cup and flow through the angular union into the plug. This arrangement is fairly satisfactory in the introduction of priming fluids, but is not efiicient for the blowing oil of carbon deposits in the plug for the reason that such carbon deposits are required to pass through a duct with-relatively short turns which result in the clogging of the duct and improper operation.

In carrying out the present invention, I form the plug with straight-through longitudinal ducts, so that the carbon exhausted therethrough travels in a substantially straight path without meeting obstructions. In this way, a more complete scavenging is effected and clogging does not result.

Another feature of the invention resides in forming the plug with a lurality of outlet ducts and controlling al of these ducts by a single tubular valve adapted to simultaneously seal or unseal all of the ducts. This construction greatly simplifies the plug and renders the control of such ducts easy and efficient In the plug ofthe present invention,-the porcelain or other insulating member extends upwardly through a reservoir or cup adapted to contain liquid to be introduced into the cylinder through the plug. The plug will function properly only so long as this porcelain'insulating element is preserved from damage or injury. In the event that the porcelain becomes cracked, short circuiting results and proper firing will not result.

In order to obviate damage to the plu I enclose orhouse that portion of the insu ating member which passes through the on within a metallic sleeve. This sleeve afl'or 5 full protection to that portion of the insulating member passing through the cup and particularly protects the insulating member against breakage due to the introduction of very cold water into the cup in severe cold weather.

Features of the invention, other than those specified, will be apparent from the hereinafter detailed description and claims, when read in conjunction with the accompanying drawings. v

The accompanying drawings illustrate one practical embodiment of the invention, but theconstruction therein shown, is to be understood as illustrative, only, and not as defining the limits of the invention.

Figure 1 is a central section of a, plug embodying the present invention; and,

Figure 2 shows the upper portion of the porcelain of the plug with the protective sleeve of the present invention associated therewith.

Referring to the drawings, 1 designates the base casting or shell of the plug which is provided with a threaded shank 2 adapted to sore-w in the tapped hole of a. cylinder in the usual manner The. upper portion 3 of the shell 1 is preferably made polygonal, hexagonal for instance, to allow of the application of a wrench thereto and is interiorly threaded to receive the threaded stem 4 of a cup or receptacle 5 adapted to be superimposed on the shell 1, as shown in Figure 1. The cup 5 is made hollow and into this cup is adapted to be introduced water or a priming fluid which may find entrance into the associated cylinder by passin through a plurality of ducts 6 arrange in an angular path coaxial 'with the plug In practice, any number ofthese ducts 6 may be employed, though I preferably use four or more. The passage of liquid content in the cup 5 throu h the ducts 6 is controlled by a valve 7 in t e form of a tubular shell, the lower edge of which is beveled bot-h interiorly and exteriorly to form valve surfaces adapted to cooperate with a substantially V-shaped valve seat 8 formed in the base of the cup 5 and constituting the valve seat. The upper portion 9 of the valve 7 is preferably hexagonal in form to allow the same to be readily grasped and immediately below this hexagonal portion the valve is threaded as at 10 for threaded engagement with the interior of the upper portion of the cup which is complementarily threaded. By rotating the valve 7, it may, b virtue of its threaded engagement with tile cup, be raised or lowered, to seat or unseat with res ect to the seat 8 for the purpose of permitting liquid to flow through the ducts 6 or for the purpose of sealing said ducts.

It will be noted that the ducts 6 are straight and constitute a straight-Way pas sage through the base of the cup, so that liquid introduced through the plug into the associated cylinder travels in a straight path and this is also true of carbon deposits which may be blown out. through the lug by wa of the ductsfi when the valve is elevat Extending directly through the plug and coaxial therewith is a central electrode 11 encased in an insulating member 12 of any suitable material, but preferably porcelain. he porcelain is provided intermediate its ends with an enlarged cylindrical portion 13 from the top of which a smaller cylinT drical portion 14 extends upwardly through the .cup 5 and beyond the top thereof. A binding nut 15 cooperaltes with the electrode 11 above the porcelain and provides means for securing an ignition lead to the plug. In accordance with the present invention, the cylindrical portion 14 of the porcelain is adapted to be embraced by a metallic sleeve 16, which may be made of any suitable metal, but is preferably of copper. This sleeve has a. shoulder 17 near its bottom, so that when the sleeve is passed up wardly through a central opening in the base of the cup, the shoulder 17 will come to a seat with a shoulder 18 formed in the cup casting. The sleeve 16 is maintained in position in'the cup and the porcelain 12 in cooperative engagement with the sleeve by means of a tubular jamb nut 19, which threads into the interior of the stem 4 of the cup and is provided interiorly with a shoulder 20 adapted to force an'inltermediate gasket 21 into engagement with the cylindrical portion 13 of the porcelain.

When the jamb nut 19 is firmly screwed into place, it forces the cylindrical portion 13 of the porcelain firmly to a seat with the lower edge of the sleeve 16 and simultaneously forces the shoulder 17 of said sleeve to a seat with the shoulder 18 on the interior of the cup.

The pressure applied by the j amb nut 19 will serve to effect a tight seal capable of precluding leakage of compression and this 1s particu arly so when 'the sleeve 16 is made of relatively soft copper. The jamb nut 19 will then cause the shoulder 17 of the sleeve to tightly come, to a seat with the shoulder 18 and will also cause the enlarged cylindrical portion 13 of the orcelain to firmly seat on the lower end 0 the sleeve.

In practice, the sleeve 16 is preferably made of such length that it will extend substantially to the top of the cup, so that when liquids are introduced into the cup, they do not come into direct contact with the porcelain. This is particularly important in severe cold weather'when the introduction of cold water into the cup would be apt to crack the hot porcelain if it were allowed to impinge the same.

In practice, the top of the cup ma be closed by a suitable cover, though I ave found that none is essential and I may also include in the plug construction a vibrating ring 21 positioned for vertical reciprocation in the plug shell 1 and functioning to jar carbon deposits free, so that they may be blown out through the plug when the valve 9 is unseated.

It will be understood that when the vibrator ring 21 is employed, it is alternately operated by gravity and the force of successive explosions in the associated cylinder to be automatically vibrated or reciprocated and produce sufiicient vibration in the plug to jar loose carbon deposits.

In practice, I have found that when a plug constructed as described is in use, decarbonizing liquids as well as priming fluids may be eflicientl introduced into the plug-chamber below t e cup 5, and thence into the associated cylinder with which the plug chamber is at all times in communication, by simply introducing the liquid into the cup and thereafter unseating the valve 7 through rotation of the same. Carbon and oil deposits may be as efiiciently blown out of the plug chamber by way of the ducts 6 when the valve 7 is unseated. However, when the valve is seated, the two-wa beveled edge thereof engages with the V shaped seat in such manner as to form a tight seal adapted to properly hold compressilon during the normal operations of the It will be apparent from. the foregoing detailed description of the invention that the plug of this invention embodies several features of novelty, some of which may be employed in plug construction without necessarily employing all.

I am further aware that the plug may be Having thus fully described the invention,

what I claim as new and desire to secure by Letters Patent is:

l. A spark plug, the upper portion of which is provided with a cup and the lower portion of which is provided with a plug chamber adapted for unrestricted communication with an associated engine cylinder, a plurality of ducts extending from the interior of the cup to the plug chamber, all of which ducts are posit1oned exteriorly of and at the same distance from, the axis or the plug, and a tubular sleeve valve having threaded engagement with the interior of the cup and adapted to be rotated to bring the lower edge of the valve into or out of cooperative relation with the ducts for the purpose of sealing or unsealing the same.

2. A spark lug, the upper portion of which is provi ed with a on having an annular channel in its base, w ich channel is coaxial with the plug, and the lower portion of which plu is provided with a plug chamber adapted f or unrestricted communication within an associated cylinder, a plurality 0t ducts leading from the baseof the annular channel to the plu chamber, and a sleeve valve having thre ed engagement with the interior of the cup, the inner end of said sleeve-valve being shaped 'to seat in the annular channel for the purpose of sealing all the ducts simultaneously.

3.. A spark plug provided in its upper portion with a reservolr and in its lower portion with a plug chamber, the latter of which is in unrestricted communication at all times with an associated cylinder, strai ht ducts leading from the reservoir to the p ug chamber, 01f center of the plug chamber and parallelto one another and to the axis of the plug, and a rotary tubular valve for controlling all of said ducts simultaneousl 4. A spark plug embodying a shell adapted for threaded cooperation with a tapped hole of a cylinder, a cup provided with a threaded shank adapted to be screwed into the threaded top of the shell, said cup being further provided with ducts leading from the interior thereof through the threaded shank for the purpose of delivering liquid from the interior of the cup into the shell, all of said ducts being ofi center of the cup and arranged in annular relation, and a common valve member for controlling the flow of liquid through all of said ducts.

In testimony whereof I have signed the foregoing specification.

I EDWARD T. CURRAN. 

